The primary aim of the proposed research is the development of an emotional regulation skills training treatment for binge eating disorder(BED). BED is often associated with obesity, the physical complications of obesity, and comorbid psychopathology. Current treatments for BED result in about a 50 percent recovery rate, indicating the need for further treatment development. The affect regulation model of binge eating is supported by a substantial body of research, yet has been ignored in the generation of treatment for BED. Dialectical Behavior Therapy (DBT), a treatment developed for borderline personality disorder, is based in part on the theory that impulsive borderline behaviors are maladaptive attempts at affect regulation. The proposed study has three phases: 1. development of an emotional regulation skills training treatment protocol for BED, adapted from DBT; 2. pretesting the treatment protocol with two separate cohorts of women with BED (N=20), and refinement of the treatment during the pretesting period; 3. a controlled pilot study (N=40) to test the efficacy of the manualized treatment in reducing binge eating and to estimate effect size in preparation for a full-scale randomized clinical trial (RCT). Twenty women will serve as assessment only controls and 20 women will receive the emotional regulation skills training treatment which will be administered in a group format over 20 treatment sessions. The principal outcome measures will be binge eating and weight. Measures of Axis I disorders, Axis II personality disorders, affect regulation, eating disorder pathology and general psychiatric symptomatology will be obtained and analyzed. Measures of therapist' adherence to the treatment as prescribed and mechanisms of change willbe developed and pretested during phases two and three of the study. The development and standardization of an emotion regulation treatment for BED, if found to be effective, has the potential to provide important treatment advances of the eating disorders in general. For example, the emotion regulation treatment could be applied to the treatment of binge eating in patients with bulimia nervosa, and the new treatment may benefit the 50 percent of patients who do not respond to the treatments currently available. Finally, this developmental research will set the stage for the design of a full-scale RCT which will compare the new treatment with alternative treatments for BED, and examine which treatment works best for which patients and investigate mechanisms of change.